The basic diffrence is Incident Management is a process in itself and 2nd level support is a function.

Incident analyst/ Incident manager primarily needs to judge/analyse an incident and accordingly assign the Incident to specific support teams and is accountable for the resolution of the incident...whereas the support team is responsible to either investigate or provide a solution to that Incident andsend it back to the IM.

So idealy an Incident managers role is completely diffrent than of a second level support , however depending on the size and capacity of an organization a specific second level support can also take up the role of an Incident Manager

Not sure if this clarified your query, however I will strongly reccommend you to go through the ITIL books for a better understanding

Thanks for your reply.
I'm studying HP Service Manager tool. HP also provides best pratices of ITIL processes for using this tool.
In the Incident Management process, HP recommends using 3 roles for this one, these are: Incident Manager, Inciden Coordinator, Incident Analyst. For the first 2 roles, I can understand them. But the last one, I have the confusion that I mentioned in my previous post.

Simply put, Guruvn, 2nd-level support personnel wear the Incident Management "hat" while they are working on incidents. They follow the same process as the Service Desk analysts do when the SDAs are working on incidents. It's generally a good practice that the 2nd- or 3rd-level support personnel don't perform the closure procedures but it's not forbidden._________________Ruth Mason
USA